Worksites, such as, for example, mines, landfills, quarries, excavation sites, etc., commonly have vehicles operating on the worksites' surfaces performing a variety of tasks. For example, at an excavation site, the surface is altered by excavation vehicles and/or other equipment. Due to the nature of worksites, the surfaces can be obstructed by a variety of obstacles, such as, for example, uneven terrain, equipment, vehicles, workers, worksite infrastructure (e.g., buildings), and/or other objects.
Vehicles operating on the worksites need to avoid such obstacles to prevent damage to the vehicles, entering impassible terrain, worker injury, and/or other inconveniences. Obstacle avoidance, however, can be difficult under some circumstances. For example, some vehicles offer poor visibility of the worksite. Other vehicles may be remotely controlled, and the vehicle operator may be relying on a video display of the worksite in controlling the vehicle. The obstacles may be difficult to perceive from the video display and/or left out altogether. Still other vehicles are autonomously controlled (i.e., unmanned), and an operator may not be present to determine whether a particular obstacle should be avoided and/or to control the vehicle to avoid the obstacle.
One system for detecting an obstacle is disclosed by U.S. Pat. No. 7,272,474 to Stentz et al. (“the '474 patent”). The system of the '474 patent divides a terrain surface map into a plurality of terrain cells. The system then determines vehicle control data for the terrain cells along a planned global path of an unmanned vehicle. Specifically, local path segments along the global path are determined to avoid vehicle entry into terrain cells in which a maximum pitch or roll angle is predicted to be exceeded; the minimum ground clearance for a vehicle cannot be maintained; and the suspension limits of the vehicle are predicted to be exceeded.
While the system of the '474 patent may help a vehicle avoid some obstacles, its application may be limited. Some obstacles may not be detectable based only on the terrain surface map. For example, some terrain cells that would not cause the vehicle to exceed a maximum pitch or roll angle nonetheless should not be entered, such as in a case where a feature beneath the surface creates an obstacle not entirely evident on the surface.
This disclosure is directed to overcoming one or more of the problems set forth above.